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export default function maxEqualFreq(nums: number[]) {    const freq = new Map<number, number>();    const count = new Map<number, number>();    let res = 0,        maxFreq = 0;    for (let i = 0; i < nums.length; i++) {        const count_old = count.get(nums[i]) ?? 0;        if (count_old > 0) {            freq.set(count_old, (freq.get(count_old) ?? 0) - 1);        }        count.set(nums[i], count_old + 1);        const curCount = count.get(nums[i]) ?? 0;        maxFreq = Math.max(maxFreq, curCount);
        freq.set(curCount, (freq.get(count.get(nums[i]) ?? 0) ?? 0) + 1);        const maxFreqCount = freq.get(maxFreq) ?? 0;        const ok = maxFreq === 1 ||            (maxFreqCount * maxFreq +                            (freq.get(maxFreq - 1) ?? 0) * (maxFreq - 1) ===                    i + 1 &&                maxFreqCount === 1) ||            (maxFreqCount * maxFreq + 1 === i + 1 && freq.get(1) === 1);        if (ok) {            res = Math.max(res, i + 1);        }    }    return res;}